JPH04331271A - Ink for gravure - Google Patents

Abstract

A gravure printing ink comprising, a vehicle having a binder dissolved in a hydrocarbon solvent and a pigment dispersed therein, wherein the binder is a modified rosin resinate prepared by reacting a rosin modified by reaction with a dienophile to form a rosin adduct, and reacting the rosin adduct with from about 0.1% to about 5.0% by weight of the resinate of a reactive compound of a metal belonging to Group I of the Periodic Table to form a resinate.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION This invention relates to gravure printing inks having vehicles containing improved rosin resinate solutions. In particular, this invention relates to improved rosin resinates modified with Group I metals, methods of producing the modified rosin resinates, and the use of the modified rosin resinates in vehicles for gravure printing inks. It is.

0002

BACKGROUND OF THE INVENTION Gravure printing inks generally include a pigment and a vehicle containing a binder to carry the pigment. Research is underway to reduce the cost of printing ink binders, but ink performance requirements must be maintained while attempting to reduce cost. As printing technology develops, printing speeds increase, and various ink properties such as gloss, drying properties, tackiness, persistence, film formation, film hardness (abrasion resistance), dilutability, The requirements for printability, color development, resistance to static migration or rubbing, compatibility and stability have become very important on the binder supply side. All of these properties are influenced by the binder or resin used in formulating the printing ink.

For many years, rosin has been used as a binder in vehicles for printing inks. For example, Erikson et al. U.S. Pat.
No. 9,135, Jones et al. U.S. Pat. No. 2,393,637, and U.S. Pat. No. 4,39
No. 8,016 both disclose rosin-modified phenolic resins for use in vehicles for offset printing inks. Yoshioha et al. U.S. Patent No. 3
, 468, 829 and Rudolphy
) and other U.S. Pat. Nos. 4,198,329 and AmericanInk Ma
ker) F.G. Oswald (F.G. Oswald)
“Rosin Derivatives for Inks” (194
5) all disclose rosin esters used in printing ink compositions.

Historically, problems faced by gravure printing inks containing rosin resinates include resinates,
In particular, the compatibility of metal rosin resinates with cellulose reinforcing fillers, such as ethyl hydroxyethyl cellulose (EHEC) solutions, and the stability of yellow pigment inks. The ways to solve these problems are diametrically opposed. EHEC
One way to improve the compatibility of is to increase the water content level within the resinate, but yellow pigments are sensitive to moisture and increasing the water content level will negatively impact the stability of the yellow pigment. give. One way to improve the stability of yellow pigments is to eliminate zinc from the metal resinate preparation, but this would result in a loss of EHEC compatibility.

In the field of gravure printing inks, there is a need for inks that exhibit high performance characteristics at low cost. There is also a need for a gravure printing ink that can improve the stability of yellow pigments and improve the compatibility with ethylhydroxyethyl cellulose without degrading print quality. moreover,
There is also a need in the art for homogenized printing ink vehicles that exhibit consistent properties.

[0006]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a gravure printing ink having a vehicle containing a rosin resinate improved by modification with a compound of a metal belonging to group I of the periodic table. The goal is to provide the following. Another object of the present invention is to provide a rosin resinate containing a compound of a metal belonging to Group I of the Periodic Table. A further object of the present invention is to provide a method of making modified rosin resinates that are particularly useful as components of printing ink vehicles. Other objects, features and advantages of the invention will become apparent from the detailed description below.

[0007]

SUMMARY OF THE INVENTION The present invention is a gravure printing ink having a vehicle having a binder dissolved in a hydrocarbon solvent and a pigment dispersed therein. The binder is a modified rosin resinate produced by reacting and modifying rosin with a dienophile to form a rosin adduct, and reacting the rosin adduct with a compound of a metal belonging to group I of the periodic table. have. According to a variant embodiment, the rosin adduct is reacted with zinc in a hydrocarbon solvent simultaneously with or before reacting the rosin adduct with a compound of a metal belonging to Group I of the Periodic Table.

[0008] The metal resin acid salt of the present invention has a melting point of 160°C.
In view of the above, it is desirable that the material has excellent dilutability with hydrocarbon solvents. Metal resinate solutions generally have the following properties: Volume viscosity at 25°C (Brocfield
kfield), Cps) 2000-400
0 colors (Gardner color number)
10-17
Non-volatile content%
5
8.2-62.0 Cardner viscosity at 25°C

It has been found that the gravure printing ink composition according to the present invention has improved yellow pigment stability, improved EHEC compatibility, and improved red and blue ink color development.

[0009]

EXAMPLES The rosin used in the present invention may be tall oil rosin, gum rosin or wood rosin. Rosin is primarily a mixture of fused cyclic monocarboxylic acids represented by levopimaric acid and abietic acid, both of which are susceptible to many chemical modifications.

Tall oil rosin is a crude tall oil obtained by acidifying the "black liquor soap" skimmed from the concentrated alkaline cooking liquor runoff from the paper pulp in the Kraft or sulfate process for papermaking. separated from Fractional distillation of crude tall oil produces tall oil rosin and fatty acids. The tall oil rosin used in the present invention preferably contains at least 80% rosin acid, preferably about 95-97% rosin acid. However, it is to be understood that the present invention contemplates the use of tall oil rosin with much lower rosin content, for example, containing about 30% rosin acid. Other substances are fatty acids and unsaponifiables.

Gum rosin is produced by spontaneous separation of some of the hydrophilic components of the sap and associated plant fluids obtained from the cambium of trees, gradually converting them into solids that are increasingly hydrophobic. Pine gum contains about 80% gum rosin and about 20% turpentine.

Wood rosin is obtained either by natural evaporation of the oil from the exudate or by resinification of the oleoresin gradually retained in the conduits of the sapwood and heartwood. The trunk of the pine tree is
It is extremely valuable because it can be extracted with hexane or high-boiling paraffins and fractionated to yield wood rosin, wood turpentine, and other turpentine-related substances.

[0013] The rosin is placed in a reactor and heated until it melts. The reaction is carried out with suitable equipment, i.e. a thermometer, a stirrer and a distillation column to separate the distilled water from the reactants, and optionally a Dean Stark (d
(Ean Stark) in a container equipped with a trap. The molten rosin is agitated as soon as the melt process allows agitation, and agitation continues throughout the process.

The dienophile is added to the molten rosin and the mixture is heated to cause a Diels-Alder (cycloaddition) reaction between the dienophile and the rosin. Suitable dienophiles for reaction with rosin include fumaric acid, maleic acid, acrylic acid, methacrylic acid, itaconic acid, citraconic acid and maleic anhydride. Although less preferred, other dienophiles may be substituted. The dienophile is preferably used in an amount of about 0.0% per equivalent of rosin.
16 to about 1.0 equivalents, preferably about 0.3 to about 0.6 equivalents per equivalent of rosin.

The reaction temperature must be between the melting point of the rosin and the boiling point of the dienophile. The optimum reaction temperature is selected depending on the rosin and dienophile used, but is generally about 150 to about 250°C, preferably about 20°C.
0 to about 210°C. Heating is continued until a rosin adduct with an acid number of about 210-220 is produced, typically taking 1-3 hours. The reaction may be carried out under an inert gas blanket such as nitrogen. The rosin adduct is then cooled, preferably to a temperature of about 100° C. to about room temperature, and then dissolved in a hydrocarbon solvent to form a molten rosin adduct. Any hydrocarbon solvent commonly used in gravure printing inks is suitable.

[0016] Next, the rosin adduct is added in an amount of about 0.1 to about 5.
0% by weight, preferably about 0.2 to about 1.0% by weight of a compound of a metal belonging to Group I of the Periodic Table. Metals belonging to group I are preferably lithium, sodium and potassium. Group I metals are used in the form of metal salts, usually added to a hydrocarbon solvent to react with the dissolved rosin adduct. Typical metal compounds are hydroxides and nitrates. The reactants may be heated, usually to reflux temperature, and the water of reaction may be removed by azeotropic distillation. The metal resinate is dissolved in a suitable hydrocarbon solvent to form a metal resinate solution.

If desired, the dienophile/rosin adduct is reacted with a slurry of a zinc compound dissolved in a hydrocarbon solvent, either simultaneously with or subsequent to the reaction with the Group I metal. Suitable zinc compounds include metallic zinc or zinc oxide or hydroxide. The reaction temperature depends on the rosin adduct and zinc compound, but is generally below the reflux temperature, ie, about 100-120°C. The reaction can also be accelerated using catalysts such as dibutyl tin oxide or butyl stannate. The desired amount of zinc compound for the adduct is a reaction equivalent or less. Generally, from about 2% to about 8% by weight of the weight of the rosin adduct.
, preferably about 4% to about 7% by weight zinc. Calcium hydroxide (lime) may be used in place of some or all of the zinc in this reaction. Using hydrocarbon solvents such as those commonly used in printing ink vehicles,
A resinate solution may also be formed.

Another feature of the present invention is to take advantage of the good dilutability of modified rosin resinates. Conveniently, any of the solvents commonly used in gravure printing ink vehicles, such as Lactol Spirits® from Union Oil Co.,
Dissolve the resinate in a hydrocarbon solvent such as naphtha, toluene and mixtures thereof. The amount of resinate dissolved will vary depending on the hydrocarbon solvent used and the desired viscosity.

Printing ink compositions prepared in accordance with the present invention are prepared in a manner similar to conventional printing ink compositions, except that the resinates of the present invention are used in the ink vehicle. Printing ink compositions, particularly gravure printing ink compositions, generally include pigments, clays, hydrocarbon solvents, resinates,
It is produced by dispersing lecithin and other ingredients commonly used in printing inks in a mill. Pigments used in printing ink compositions are known to those skilled in the art of printing.

The flexibility and abrasion resistance of the printed surface can be improved by adding reinforcing fillers such as ethylcellulose, especially ethylhydroxyethylcellulose. Ethylcellulose is generally mixed into a vehicle in the form of a hydrocarbon solution. Reinforcing fillers are added in amounts up to about 12% by weight of the final product, preferably up to about 10%.

The viscosity of the vehicle can be selected from a wide range depending on the type of pigment to be mixed and the mixer;
Desirably, it is around 30 to 150 cps at °C. The rosin resinate is at a concentration such that the viscosity of the vehicle is maintained within the above range, and concentrations of 30-50% by weight are widely used.

The most common mixing ratios of vehicle, pigment and reinforcing filler are as follows.
Desired range Optimal range ──
──────────────────────────
─ Vehicle (parts by weight) 60-97
80-90 Pigment (parts by weight)
3-40 10
~20 ────────────────────
──────── Since the mixing ratio changes depending on the use of the ink, the present invention is not limited to the above range.

The advantages of this improved resinate solution gravure printing ink are improved stability of the yellow ink, improved compatibility with ethyl hydroxyethyl cellulose (EHEC), and improved color development of phthalo blue and lysole bean pigments. be.

The invention will be further illustrated by the following experimental examples, but they are not intended to limit the invention. All parts are parts by weight unless otherwise specified. Experiment 1. In a suitable reaction vessel equipped with an overhead stirrer, condenser, and Dienst-Stark trap, tall oil rosin 1.
000 parts were added to form a Diels-Alder adduct. 40 parts by weight of maleic anhydride was added to the rosin. Inert gas was turned off. The complete maleic adduct was formed by heating the reaction mixture to 210°C and holding for 1 hour. The reactor was cooled and 400 parts of toluene was added to form a molten rosin adduct.

Experiment 2 A zinc-modified resinate used as a standard was produced from the product of Experiment 1. The molten rosin adduct from Run 1 was placed in a reactor, the temperature was adjusted to 98°C, and a slurry of 36 parts zinc metal and 177 parts toluene was added. After completion of the zinc reaction, the reactor was cooled to 68°C and lime (CaOH) 8
A slurry of 2 parts and 177 parts toluene was added. The reaction was heated to reflux temperature and the water of reaction was removed by azeotropic distillation. The properties of this product are shown in Table 1.

Experiment 3 A sodium modified resinate was produced from the rosin adduct of Experiment 1. The dissolved rosin adduct formed according to Experiment 1 was placed in a reactor at 98°C and 10 parts of 50% sodium hydroxide solution was added. 36 parts zinc and 177 parts toluene
of slurry was added. After completion of the zinc reaction, the reactor was
It was cooled to 8°C and a slurry of 82 parts lime and 177 parts toluene was added. The reaction was then heated to reflux temperature and the water of reaction was removed by azeotropic distillation. The physical properties of this product are shown in Table 1.

Experiment 4 A lithium-modified resinate was produced from the resinate of Experiment 1. The molten rosin adduct formed according to Experiment 1 was
C. and 15 parts of a 33-1/3% aqueous lithium nitrate solution was added followed by a slurry of 36 parts zinc and 177 parts toluene. After completion of the zinc reaction, the reactor was
After cooling to 0.degree. C., a slurry of 82 parts lime and 177 parts toluene was added. The reaction was then heated to reflux temperature and the water of reaction was removed by azeotropic distillation. The physical properties of this product are shown in Table 1.

Experiment 5 A sodium modified resinate was produced from the resinate of Experiment 1. 9 molten rosin adducts formed according to Experiment 1
It was cooled to 8° C. and 10 parts of a 50% aqueous sodium nitrate solution was added, followed by a slurry of 36 parts of zinc and 177 parts of toluene. After the zinc reaction was complete, the reactor was cooled to 68° C. and a slurry of 82 parts lime and 177 parts toluene was added. The reaction was then heated to reflux temperature and the water of reaction was removed by azeotropic distillation. The physical properties of this product are shown in Table 1.

Experiment 6 A potassium modified resinate was produced from the resinate of Experiment 1. The molten rosin adduct formed according to Experiment 1 was
It was cooled to 0.degree. C. and 10 parts of a 50% aqueous potassium hydroxide solution was added, followed by a slurry of 36 parts of zinc and 177 parts of toluene. After the zinc reaction was complete, the reactor was cooled to 68° C. and a slurry of 82 parts lime and 177 parts toluene was added. The reaction was then heated to reflux temperature and the water of reaction was removed by azeotropic distillation. The physical properties of this product are shown in Table 1.

Experiment 7 A lithium-modified resinate was produced from the resinate of Experiment 1. The melt adduct formed according to Experiment 1 was cooled to 98° C. and 10 parts of a 50% aqueous lithium hydroxide solution was added followed by a slurry of 36 parts zinc and 177 parts toluene. After the zinc reaction was complete, the reactor was cooled to 68° C. and a slurry of 82 parts lime and 177 parts toluene was added. The reaction was then heated to reflux temperature and the water of reaction was removed by azeotropic distillation. The physical properties of this product are shown in Table 1
is shown.

Table 1──────
──────────────────────────
── Experiment 2
Experiment 3 Experiment 4 Experiment 5 Experiment 6 Experiment 7──
──────────────────────────
────── Modification Standard NaOH LiNO3 NaNO3
KOH LiOH Viscosity at 25℃
X-Z Z+ Y-Z
U-V Y-Z Y-Z
(Gardner) Number of Gardner colors 16 16
17 14 15
14 Non-volatile content % 62.5
60.6 62 61.0
61.3 61.2 Dilution*
73ml 75ml 75m
l 74ml 75ml 75ml
Melting point (℃) 173 172
175 170 178
176──────────────────
────────────── *18” Shell #2
100 grams of toluene for

Experiment 8 The resinate solutions of Experiments 2-7 were tested for compatibility with ethylhydroxyethylcellulose. 40 grams of each resinate was mixed with 10 grams of 7% EHEC solution. The solution was stirred manually and then mixed with Red Devil.
l) Placed on paint shaker for 15 minutes. 1
The mixture was tested for EHEC compatibility after 5 hours. The results are shown in Table 2.

The EHEC compatibility of all five resinates produced with the metal resinates of the present invention was better than that of the standard resinate produced without the metals of the present invention. Ta.

Experiment 9 The resinates of Experiments 2-7 were tested for yellow pigment stability. A yellow base ink was produced with the following composition. Resin acid salt 50 parts AAA yellow pigment 25 parts Toluene 25 parts

[0035]
A diluent yellow base was produced with print-ready ink using the following composition. Glidebase (as above) 32 parts resinate
50 parts toluene 1
Part 8

[0036] The diluted ink was heated to 110°F (43.4°C).
) and stored in an oven for 7 days. After 7 days, the original base was diluted again using the same dilution composition. Fresh diluted ink and 7 day old ink were drawn onto both uncoated and coated paper using a #3 draw down rod. The results are shown in Table 3.

Table 3------
──────────────────────────
──── Type
Result────────────────────
──────────────── Experiment 2
Standard After 7 days, the sample becomes thinner and changes to a green tone Experiment 3 NaOH
Experiment 4 LiN with no decrease in strength or color change
O3 Slight decrease in strength (better than standard) Experiment 5 NaNO3 Slight decrease in strength (better than standard) Experiment 6 KO
H: Very slight decrease in strength (better than standard) Experiment 7 LiOH: Very slight decrease in strength (better than standard)──────────
────────────────────────

[
A Macbeth colorimeter was used to determine the difference in color change between a standard (group I metal free) resinate and a resinate produced using sodium hydroxide on coated and uncoated paper. Both coated papers were investigated. The old standard resinate changed to a green tint in both coated and uncoated papers, and the strength decreased significantly in the coated paper. The older sodium-modified resinates had a very slight change in color (slightly towards the red side), the strength was the same on coated paper, and it became darker on uncoated paper.

Although the invention has been described with reference to specific materials, procedures, and experiments, it is to be understood that the invention is not limited to the particular materials, combinations of materials, and procedures selected therefor. It will be understood by those skilled in the art that various changes may be made to these details.

Claims (32)

[Claims] 1. A printing ink composition comprising a vehicle having a binder dissolved in a hydrocarbon solvent and a pigment dispersed therein, the binder reacting molten rosin with dienophile. A printing ink composition comprising a modified rosin resinate produced by reacting the rosin adduct to form a rosin adduct and reacting the rosin adduct with a compound of a metal belonging to Group I of the Periodic Table. 2. The printing ink composition of claim 1, wherein said rosin is selected from tall oil rosin, gum rosin and wood rosin. 3. The printing ink composition of claim 1, wherein the dienophile is selected from fumaric acid, maleic acid, acrylic acid, methacrylic acid, citraconic acid, itaconic acid and maleic anhydride. 4. The printing ink composition according to claim 1, wherein said compound of a metal belonging to Group I of the Periodic Table is a metal salt selected from sodium salts, potassium salts and lithium salts. 5. The printing ink composition according to claim 1, wherein the dienophile is subjected to the reaction in a proportion of 0.16 to 1.0 equivalents per equivalent of rosin. 6. The printing ink composition according to claim 3, wherein the dienophile is subjected to the reaction in a proportion of 0.3 to 0.6 equivalents per equivalent of rosin. 7. The printing ink composition according to claim 4, wherein the compound of a metal belonging to Group I of the Periodic Table is subjected to the reaction in an amount of 0.1 to 5.0% based on the weight of the resinate. thing. 8. The printing ink composition according to claim 1, wherein said compound of a metal belonging to group I of the periodic table is subjected to the reaction in an amount of 0.2 to 1.0% based on the weight of the resinate. thing. 9. The printing ink composition of claim 1, wherein the binder is further modified by reaction with zinc in an amount of 2% to 10% by weight relative to the rosin adduct. 10. The ink composition is a gravure printing ink composition comprising 3 to 40 parts by weight of pigment and up to 12% by weight of reinforcing filler based on 60 to 97 parts by weight of vehicle. The printing ink composition according to claim 1 or 9. 11. The ink composition is a gravure printing ink composition comprising 10 to 20 parts by weight of pigment and up to 10% by weight of ethylhydroxyethylcellulose based on 80 to 90 parts by weight of vehicle. Claim 1
or the printing ink composition of No. 9. 12. Forming a rosin adduct by reacting molten rosin with a dienophile, forming a rosin resinate by reacting the rosin adduct with a compound of a metal belonging to Group I of the periodic table, and forming a rosin resinate by reacting the rosin with a dienophile. A modified rosin resinate solution having the product obtained by dissolving the acid salt in a suitable hydrocarbon solvent. 13. Claim 1, wherein the rosin is selected from tall oil rosin, gum rosin, and wood rosin.
2 rosin resinate. 14. The dienophile is fumaric acid, maleic acid, acrylic acid, methacrylic acid, citraconic acid,
13. The rosin resinate of claim 12 selected from itaconic acid and maleic anhydride. 15. The rosin resinate of claim 12, wherein said compound of a metal belonging to Group I of the Periodic Table is selected from sodium salts, potassium salts and lithium. 16. The hydrocarbon solvent is Lactol Spirits®.
13. The rosin resinate of claim 12 selected from , naphtha, toluene and mixtures thereof. 17. The rosin resinate of claim 12, wherein the dissolved reaction product is reacted with 2 to 10% by weight of a compound selected from zinc, calcium and mixtures thereof, based on the rosin adduct. 18. The hydrocarbon solvent is Lactol Spirits®.
18. The rosin resinate of claim 12 or 17 selected from , naphtha and toluene. 19. The rosin resinate according to claim 14, wherein the dienophile is subjected to the reaction in a proportion of 0.16 to 1.0 equivalents per equivalent of rosin. 20. The rosin resinate according to claim 14, wherein the dienophile is subjected to the reaction in a proportion of 0.3 to 0.6 equivalents per equivalent of rosin. 21. The rosin resin acid according to claim 12, wherein the compound of a metal belonging to Group I of the periodic table is subjected to the reaction in an amount of 0.1 to 5.0% based on the weight of the resin acid salt. salt. 22. The rosin resin acid according to claim 12, wherein the compound of a metal belonging to Group I of the Periodic Table is subjected to the reaction in an amount of 0.2 to 1.0% based on the weight of the resin acid salt. salt. 23. The rosin resinate according to claim 12, wherein the resinate has a melting point of 160°C or higher and a Gardner viscosity of Z at 25°C. 24. A method of producing a rosin resinate particularly suitable as a component of a printing ink composition, comprising:
a) Molten tall oil rosin is mixed with a dienophile selected from fumaric acid, maleic acid, acrylic acid, methacrylic acid, citraconic acid, itaconic acid and maleic anhydride in an amount of 0.16 to 1.0% per equivalent of rosin. (b) cooling said rosin adduct to a temperature from about room temperature to 100° C. and dissolving said rosin adduct in a hydrocarbon solvent to form a dissolved rosin adduct; (c) forming said molten rosin adduct to 0.1
reacting with ~5.0% by weight of a compound of a metal belonging to group I of the periodic table to form a reaction product. 25. The reaction in step (a) is from 150 to 25
25. The method of claim 24, carried out at a temperature of 0<0>C. 26. The reaction in step (a) is 200 to 21
At a temperature of 0℃, the acid value of the rosin adduct is 210-22.
25. The method of claim 24, wherein the method is performed until zero. 27. The method according to claim 24, wherein the dienophile is subjected to the reaction at a ratio of 0.3 to 0.6 equivalents per equivalent of rosin. 28. The method of claim 24 further comprising the step of reacting the molten rosin with 2-10% by weight zinc. 29. The method of claim 24, wherein the reaction product is dissolved in a hydrocarbon solvent. 30. The hydrocarbon solvent is Lactol Spirits®.
30. The method of claim 29, wherein the method is selected from , naphtha, toluene and mixtures thereof. 31. The method of claim 24, wherein said compound of a metal belonging to Group I of the Periodic Table is selected from among sodium salts, potassium salts and lithium salts. 32. The reaction product is 0.2 to 1.0
25. The method of claim 24, wherein the compound is reacted with % by weight of a compound of a metal selected from Group I of the Periodic Table.